What it means
A control module received invalid data from battery charger control module B. The code identifies a data validity fault; the specific affected function depends on the vehicle.
At a glance
- Usually lights the warning light of the system that lost communication
- The engine or gearbox may go into limp mode
How it works
Battery charger control module B reports charging information used by other modules to manage the vehicle's charging functions. U04BE is set when a receiving module judges module B's data invalid, which may limit charging even if the code does not identify a failed charger or battery.
Common causes
Most likely first.
- Fault in the transmitting module
- Network wiring or connector fault
- Module power or ground fault
- Software or configuration mismatch
Symptoms
- Charging functions may be limited or unavailable
- Related communication codes or charging-system warnings may appear
How to diagnose it
- Record freeze-frame data and scan charging, battery, and hybrid or electric-drive modules for related codes.
- Check live data from battery charger control module B for missing, implausible, or invalid status and compare it with the observed charging behavior.
- Inspect module B's connectors and network wiring for looseness, corrosion, moisture, or physical damage.
- Check the module's power and ground against the manufacturer's specification, following the vehicle's high-voltage safety procedures where applicable.
- Test the relevant network wiring and connector terminals for opens, shorts, or poor connections using the vehicle wiring information.
- If wiring and supplies pass, check for applicable software or configuration issues before considering module replacement.
Common fixes
- Reconnect or repair a loose or corroded battery charger control module B connector.
- Repair damaged network wiring or connector terminals serving module B.
- Restore a faulty module power or ground connection.
- Correct an applicable software or configuration mismatch.
- Replace battery charger control module B or the receiving module only after testing confirms the source of invalid data.
Can I keep driving?
If charging is limited or unavailable, avoid relying on the vehicle for a long trip and monitor its charge state; stop if a charging warning or other serious warning appears. Do not handle high-voltage components unless trained and equipped for that work.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.